VARIABILITAS SUHU PERMUKAAN LAUT DAN KONSENTRASI KLOROFIL-A DI PERAIRAN PALABUHANRATU DAN SEKITARNYA

Abstract

The purpose of this study was to determine the variability of Sea Surface Temperature (SST) and chlorophyll-a concentration (Chl-a) in the waters of Palabuhanratu and its surroundings. This study used a combination of NOAA-AVHRR and MODIS images data for monthly SST, SeaWiFS and MODIS images for monthly Chl-a, and monthly surface wind data from the European Center for Medium Range Weather Forecasts (ECMWF). Monthly data of El Nino Southern Oscillation (ENSO) index and the Dipole Mode Index (DMI) were also used. The results showed that the range of SST for 21 years (1997-2018) was 23.14-33.45°C where the maximum SST value occurred at the end of Transition Season 1 (May), while the minimum low value was found at the beginning of Transition Season 2 (September). Chl-a for 21 years ranged from 0.063-3.363 mg/m³ where the maximum Chl-a occurred during the beginning of Transition Season 2 (September), while the minimum value was found at the end of Transition Season 1 (May). During ENSO and positive IOD occurred together, it triggered stronger Southeast wind speed and intensified upwelling event along the Palabuhanratu and its surrounding waters and caused lower SST and higher Chl-a than normal. Variabilities of the SST and Chl-a values were related to the seasonal winds, the intensity of solar radiation, the phenomenon of climate anomalies of ENSO, and Indian Ocean Dipole Mode (IODM). The evidence of higher concentration of chlorophyll-a around August-October coincided with the evidence of lower SST in the same seasons was due to the upwelling phenomenon.